


Mac's Mate

by Adiaphory



Category: It's Always Sunny in Philadelphia
Genre: Accidental Mating, Alpha!Dennis, Alpha/Beta/Omega Dynamics, Alpha/Omega, Charlie huffing glue, Dennis taking advantage of Mac, Karate, Knotting, M/M, Mac hates everything, Mac is gay, Mating, Mpreg, Non-Graphic Smut, Ocular patdowns, Omega!Mac, Successful implied MAC System, WTF, Weird Shit, failed implied DENNIS System, what even
Language: English
Status: Completed
Published: 2016-02-07
Updated: 2016-02-07
Packaged: 2018-05-18 18:56:32
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,973
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/5939599
Author URL: https://archiveofourown.org/users/Adiaphory/pseuds/Adiaphory
Summary: <blockquote class="userstuff">
              <p>Dennis takes it a step too far when he tries to DENNIS System his way into Mac's pants. The only problem? Mates can't make it to Step S: Separate Entirely.</p><p>[Super weird-ass story I found on my computer]</p>
            </blockquote>





	Mac's Mate

There were a lot of things Mac hated. He hated his full name, he hated abortions, he hated how science could be a liar sometimes, he hated how shirts always had sleeves to be ripped off, and he hated most of all that he was an omega.

It wasn’t right, was it? He was so manly and ripped and he could cultivate and harvest so much mass in such a small span of time but what does nature decide? He gets to be an omega! Not an alpha like God would have wanted. Even being a beta would have been better, or nothing at all.

But no. Omega it was.

And whenever heat came around he was locked in his apartment alone while Dennis was forced to go stay with Charlie and Frank until the coast was clear again.  All three were alphas, and that’s like insult to injury. Charlie was a goddamn alpha!

Mac angrily threw out a few kicks and punches, always practicing his karate moves, as he scrounged around the apartment looking for good nest materials.

Stupid goddamn internal instincts.

He found a few blankets in the closet and brought them back to his room, throwing them onto the bed and arranging them just so. It still wasn’t good enough, so he left and searched for more. It wasn’t long until the cushions of the couch were added along with whatever soft things he could find. There was a fine layer of sleeveless shirts on the pile and when he thought he was done, he caught a scent in the air.

Right there, on the floor outside Dennis’s door, was a sweatshirt. An old grey one that missed laundry day. Obviously Dennis forgot it, knowing better than to leave his sweaty and alpha-scented clothes around in the open during this time.

The cloth was soft in Mac’s hands and the hoodie smelled heavenly, like beer and men’s body spray and asphalt and pretzels. Like Dennis. He held it tightly to his chest and inhaled the smells and took it to his room as the final piece of the nest.

* * *

“Goddamn it,” Dennis whined. “I left my phone charger. God. Damn it.”

Charlie lifted a brow and asked, “Just borrow ours.”

“I can’t, _Charlie_. It’s not even the same phone.”

Charlie smirked and stood up, pulling his phone charger from the wall. “That’s the beauty of it! See, I found this perfectly fine charger when I was talking the trash out last week and I thought, _gee Charlie, you’d be stupid to just leave it there where anyone could have it!_ So I took it and I rigged it up to fit any phone ever.” He showed the amazing cord, which happened to be chewed on and more exposed wire than not. The end where the phone would be plugged into was just more exposed wiring where Charlie had bit it apart himself. “You just take these wires here, lick them a bit, and shove it right in your phone hole. But don’t plug it in unless you have like a microwave or something on.”

Dennis stared blankly at him. “How are you still alive?”

The shorter alpha shrugged and picked up some glue and a plastic bag. “We’re having Fancy Feast for dinner, would you care to partake in some pre-dinner huffing?”

Dennis gagged a bit and stood up. “I can’t do this again. If that was cocaine I’d be with you, buddy, but I can’t do this. This is depraved.” He stood to leave and grabbed his coat.

“Where are you going? You know you can’t go back to your place, Mac is probably already bitching out right now!”

“I DON’T CARE. I’ll keep my door locked!” He stomped out and left the apartment.

* * *

Mac was sprawled in his nest, feeling the heat coming on in waves. He always hated this part of being an omega the most. It was so hard to pick up chicks when he reeked of omega. He usually had to steal some of Dennis’s clothes and get the girls drunk enough to believe he was at least a beta.

It was too damn hot in here! He ripped his shirt off and paused to admire his own physique in the mirror. Nice. He’d totally mate him if he were an alpha. Speaking of which, why hadn’t be been mated yet? He was hot and young and he harvested so much mass! He could protect the pups, he was so—

Wait, pups?

No no no, Mac didn’t want kids or to be mated! It was his choice, damn it, he didn’t want to be some house-omega watching after some little shit kids. Dennis would probably be out all night drinking and picking up nearly underage betas at the bar while he was at home teaching his kids about how awesome God is and how to do karate and—

…did he say Dennis?

No no no, he most definitely didn’t want Dennis to mate him!

Mac huffed and left his room to do some karate in the living area where there was room and he wasn’t liable to fuck up the nest he worked so hard on. What he wasn’t expecting was to be greeted by Dennis entering the apartment as he left his room.

There was a moment of silence as they stood there, watching one another, quietly assessing the situation. Dennis’s eyes faltered and he noticed the shirtless chest, glistening with sweat and smelling very strongly of an omega in heat. Mac swallowed hard and tried not to notice the overwhelming alpha scents filling his head.

“I, uh,” Dennis stammered. “I couldn’t stay with Charlie and Frank. I don’t even know how they’re alive at this point.”

“Uh, yeah,” Mac mumbled, mind fogging. “I was just, uh, doing some karate. I’m not some omega bitch. I just, uh, karate my way through heat. I don’t need some nest… _or a mate_ ,” he added under his breath.

Dennis nodded and saw Mac’s open door, complete with a view of the very obvious nest. A single glance across the room showed the lack of cushions on the furniture and the missing articles of clothing they were prone to leave out.

“What’s that?”

“What’s what?”

“On your bed.”

“I’m… collecting laundry.”

“The couch isn’t laundry.”

“YOU DON’T KNOW SHIT, DUDE,” Mac yelled, shocked at the emotion charging his voice. He turned around and did some quick pacing, throwing a few random kicks and punches out. “Fuck you, man! You can’t just come charging into our apartment when you know you have to leave! I’m ready to be alone for a week and there you are, coming in smelling like pretzels, doing your hummingbirds in the door when you know how crazy it makes me! Fuck science and bitch-ass pheromones!”

He stopped for a moment with his hands on his hips and his head turned away. Dennis watched him but didn’t hear him. All he could hear were the crazy signals Mac was giving off. And he knew for a fact some of his own clothing was being used in that goddamn nest.

Mac wanted to mate him.

“I…” Mac choked out, “I only even room with you to keep the other alphas away! Because your smell gets on me and won’t wash off and if I lived on my own I would have been diddled by now.”

Dennis cocked his head, detecting the lie.

“But dude, you’re a major cockblock! I can’t even score with chicks because everyone thinks I’m mated already!”

Dennis took a few steps forward, Mac stilling in anticipation. He gently placed his hand on Mac’s neck, a dominant move. “I think you want to be mated.”

Mac bit his lip. “O-of course not.”

“You’re an omega and I’m an alpha. It only makes sense,” he leaned in closer and Mac shuddered at the breath on his ear. “Maybe I _should_ mate you.”

After a quick ocular pat-down Mac would see the bulge forming in Dennis’s pants. The alpha dived in for a kiss and they bumped into every possible object as they stumbled into Mac’s room, landing in the nest. Dennis took his shirt off, to which Mac obediently complimented his pecs and abs.

Pants flew off and shoes and socks were kicked to the side and they were making out on the nest-bed. Mac was grinding hard against Dennis and the alpha quickly plunged into the omega.

Heat is awesome, Dennis thought. Omegas become such whores. He thrusted sporadically into his roommate, who was rubbing his neck against Dennis’s head and taking in the scent. By the time they were through they would definitely and undeniably smell like a mated pair. They already had the lingering scents but now, oh lord now they would reek of it.

Caught up in the moment Dennis leaned down and bit on Mac’s shoulder and neck, drawing the faintest amount of blood. Mac keened and made animalistic noises that were music to the alpha’s ears.

Dennis kept working at his own orgasm and soon knotted inside the omega. He panted and went to pull out, forgetting that he couldn’t during omega-heat sex. Mac groaned and looked up into the dark eyes of Dennis. They maneuvered themselves to be on their sides, facing one another. Mac was awkwardly positioned, slightly higher on the bed and at a weird angle, but that was their own fault for not doing it the tradition Mac-on-his-knees-with-Dennis-behind method.

“Uh, Dennis?”

“Yeah, Mac?”

“How are we gonna explain this to the gang?”

“Explain what, exactly?”

Mac lifted his eyebrows and used his hand to point to his neck, were there were two bites bruising and leaving a very obvious mark.

“Oh shit,” Dennis groaned into the pillow.

“We’re mated,” Mac said a little too enthusiastically. “And dude, if you cheat on me I’m gonna bite that knot right off!”

“GOD, _WHY ME_?”

* * *

Dennis was facedown at the bar, trying to ignore the idiots surrounding him.

“You know, I always thought Mac was gay but I had no idea you were,” Dee teased.

“I’m not gay,” he muffled through his arm. “And it was a bro-mating thing. You wouldn’t understand, you stupid beta whore.”

Charlie sat back chuckling, taking a break from all the Charlie work. “Make our boy an honest man!”

“You into men now?” Frank asked from his office doorway. “Do I needta rely on Deandre to pass on my alpha genes now?” He motioned crudely to his crotch, because fuck it, he’s getting old and it’s gonna get weird.

“No, Frank,” Dee interrupted. “You don’t need a _girl_ omega for that.”

Dennis sat up straight. “What?”

“Didn’t you pay attention in health back in high school? It takes an alpha and omega to make a baby, they didn’t say they both couldn’t be dudes,” Charlie joined.

“You’re illiterate, shut up!”

The gang enjoyed their time teasing Dennis and giving him shit for mating Mac because, as they all knew, Dennis wasn’t the type to be committed and would easily leave any poor omega he mated… they also knew Mac wasn’t the type to be mated and allow his mate to leave. Dennis was purely screwed.

The front door banged open and Mac strolled in, face covered by a huge smile. “Hey, Dennis!”

“Christ, go away,” the alpha groaned again through the chuckles.

“Oh come on, Dennis, your mate wants to see you!” Dee chided.

“I do, Dee!” Mac excitedly agreed. He pulled something from his pocket, holding it up for his mate (and the rest of the gang) to see. It was a white stuck with a pink plus on the end and—oh god it was a pregnancy test. “Guess who sired a pup?”

“No… no, no, no!” Dennis cried. This was the worst thing to ever happen to him.


End file.
